Chop saw with dust collection system

ABSTRACT

A chop saw, grinding wheel, or like apparatus is disclosed herein also incorporated to an easily portable dust collection system. In a preferred embodiment, a worktable is provided with a center slot for receiving a circular saw blade. A negative pressure and resulting air flow is provided at the center slot to capture particulate matter as a byproduct of cutting the workpiece. Side slots are also disclosed to assist in particulate collection. A unique filter chamber having a cylindrical filter is additionally provided to remove dust from air and discharge the filtered air at a lateral side of the apparatus. A filter cleaning knob is additionally disclosed to assist in cleaning the filter. Of the beneficial aspects of the chop saw with dust collection system is its portability being one integral unit and the dust filter being easily cleaned and maintained.

PRIORITY CLAIM

This patent application contains subject matter claiming benefit of thepriority date of U.S. Provisional Patent Application Ser. No. 61/078,250filed on Jul. 3, 2008 and entitled A Combination Chopsaw And DustCollection System. The application additionally claims benefit of thepriority date of Ser. No. 61/152,574, filed Feb. 13, 2009 having thesame title. Accordingly, the entire contents of these provisional patentapplications are hereby expressly incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains generally to power masonry tools andrelated devices for cutting and grinding. More specifically, the presentinvention relates to power saws of the “cut-off” type and systems thatfurther maximize containment of dust contaminant while cutting cinderblock, concrete, brick, clay, stone, tile and the like.

2. Description of the Prior Art

Power saws of the “cut-off” variety have been known for some time thatemploy a rotating circular blade applied to a stationary workpiece, suchas wood, masonry or stone materials. An early version of a radial sawwas invented by Raymond De Walt in 1922. These types of saws furtherinclude what is known as a “chop saw” which may be used for cuttinglengths of pipe, steel, and other masonry objects. The chop sawcomprises a motor coupled to a circular blade (or grinding wheel)pivotally supported for manual arcuate movement relative to a supportingsurface such as a worktable.

An example of systems and methods comprising a chop saw are disclosed inU.S. Pat. No. 7,543,522 entitled “Adjustable Fence Assembly for ChopSaw,” to Chen. Some additional features known for chop saws includecompounding the blade to change its angle with respect to the horizontalplane; or a sliding compound feature so that the blade can make largercuts relative to a circular blade diameter. Some chop saws furtheremploy a laser guide such as the configuration disclosed in U.S. Pat.No. 4,257,297 entitled “Circular Saw with Visual Cut Line Indicator,” toNidbella.

Also known, is a problem of uncontrolled release of and exposure toairborne dust and particulate matter resulting from cutting a workpiece.Accordingly, government agencies such as OSHA have promulgated safetyand health requirements for wet and dry cutting. The CaliforniaOccupational Safety and Health Act of 1973 requires employers to providea safe and healthful work place and gives Cal/OSHA regulatoryjurisdiction over all public and private employers in California.Henceforth, employers must be compliant with all regulations set forthin Title 8 of The California Code of Regulations. In addition to healthissues, the dust by-products present a clean-up challenge, even if allindividuals in a contained environment have donned respirators.

Development of wet cutting devices and methods is one solution to dustabatement. In doing so, water is applied at a blade cutting edge wheredust is entrained to a fluid and directed to a holding area. While mostwet cutting methods work relatively well, they create additionalproblems of waste water pollution and environmental concerns. Further,the slurry created will adhere to cutting tool materials and componentsthat also require periodic cleaning.

Many prior art solutions have been proposed that specifically employ drymeans to control dust. Examples of such designs include, “Cutting AndDust Collecting Assembly,” by Johansson, U.S. Pat. App. Pub. No.2008/0163492, “Cutting Apparatus with Dust Discharging,” to Kodani etal., U.S. Pat. No. 7,223,161, “Dust-Free Masonry Cutting Tool,” to Bath,U.S. Pat. No. 6,595,196, “Dust Collector for A Power Tool,” by Miller etal., U.S. Pat. Pub. No. 2007/0017191, to name a few. Such solutionsgenerally may be suitable for their general purposes however none ofthese solutions are applicable for a chop saw. Yet another similardevice was proposed by one of the present inventors, Guth entitled “DustCollection System for A Masonry Saw,” U.S. Pat. No. 7,013,884, andassigned to Masonry Technology Incorporated. This dust abatement designis applicable to a masonry chop saw; however this design is not easilyportable and requires a separate hook up to a vacuum system.

In light of the above, it is an object of the present invention toprovide a Chop Saw with Dust Collection that is highly portable andlighter in weight as compared prior art solutions. More specifically, itis an object of the present invention to provide a masonry chop saw thatintegrates dust collection to a single portable unit. It is still afurther object of the present invention to provide a dry dust collectiondesign that is easily cleaned. It is still further an object of thepresent invention to provide a design that includes a variety ofinnovative features over prior designs.

BRIEF SUMMARY OF THE INVENTION

The present invention specifically addresses and alleviates the abovementioned deficiencies, more specifically, the present invention, in afirst aspect, is directed to a cut off saw comprising: a worktable forsupporting a work piece; a rotatable arm fixed to a circular saw bladeand pivotably secured to the worktable; a center slot carved out of theworktable axially aligned to the circular saw blade; a vacuum apparatusat an interior of the worktable, the vacuum apparatus providing negativepressure with respect to atmosphere at the center slot and collectingdust from the work piece created as a byproduct from use of the cut offsaw.

The invention embodiment is additionally characterized in that worktablefurther comprises: a saw motor mechanically coupled to a circular sawblade; an upper housing; and a lower dust bin connected below the upperhousing, the upper housing and lower dust bin each including a frontpanel, a back panel and first and second lateral sides, wherein theupper housing further comprises a lateral partitioning wall extendingfrom first and second later sides, the lateral partitioning walldefining a suction chamber below the center slot, and wherein the upperhousing further comprises a transverse partitioning wall defining both avacuum motor chamber and a filter chamber.

The invention embodiment is additionally characterized wherein each ofthe upper housing front panel and upper housing back panel furthercomprises a lifting handle, each of the lifting handles comprising anindentation in the upper housing front and back panels. In addition tothe center slot, the worktable further comprises a plurality of bladeslots angularly aligned to the center slot.

The cut off saw is further characterized wherein the filter chambercomprises: an access panel covering an area carved out of the firstlateral side; a filter cleaning knob connected to a first filter end capvia a connection bolt, the connection bolt penetrating a hole in theaccess panel; a panel bushing providing translational and rotationalsupport to the connection bolt; a second filter end cap, the first andsecond filter end caps together securing ends of a cylindrical mediafilter; a vacuum suction tube connected to the vacuum apparatus, thevacuum tube penetrating the transverse partitioning wall; and an annularrim protrusion extending from the vacuum suction tube, the annular rimprotrusion mating with the second filter end cap via a gasket and abearing, the second filter end cap further comprising a bearing seatacting as an abutment to the bearing.

Still further, the invention embodiment is characterized wherein theupper housing comprises a lower rim, the lower rim comprising a groovearound a perimeter thereof, and wherein the lower dust bin furthercomprises an upper rim, the upper rim comprising a groove around aperimeter thereof, and wherein the upper and lower rims comprisinggrooves are matingly and removably connected to each other.

Yet further, the invention embodiment is characterized wherein the lowerdust bin first and second lateral sides each comprise a lifting handle,the lifting handles each comprising an indentation in the first andsecond lateral sides, respectively; and wherein the lower dust binfurther comprises a latch for securing the lower dust bin to the upperhousing.

In a second aspect, the invention is a cut off saw comprising: aworktable for supporting a work piece; a saw motor mechanically coupledto a circular saw blade; a rotatable arm fixed to the circular saw bladeand pivotably secured to the worktable; a filter chamber at an interiorto the worktable, the filter chamber comprising: a cylindrical mediafilter; and a vacuum tube coupled to an interior of the cylindricalmedia filter providing negative pressure with respect to atmosphere tosaid interior of the cylindrical media filter.

The cut off saw in this embodiment may be further characterized in thatthe worktable further comprises: a center slot carved out of theworktable axially aligned to the circular saw blade; and a plurality ofblade slots angularly aligned to the center slot. Further, the filterchamber further comprises a filter cleaning flap secured to a lateralpartitioning wall at an interior of the filter chamber, the cylindricalfilter media having a plurality pleated segments about a cylindricalsurface, wherein the filter cleaning flap contacts the pleated segmentswhen the filter cleaning knob is rotated. Also, the filter chamberfurther comprises: an access panel covering an area carved out of thefirst lateral side; and a filter cleaning knob connected to a firstfilter end cap via a connection bolt, the connection bolt penetrating ahole in the access panel. Still further, the filter chamber furthercomprises: a panel bushing providing translational and rotationalsupport to the connection bolt; and a second filter end cap, the firstand second filter end caps together securing ends of a cylindrical mediafilter. Yet still further, the filter chamber further comprises: avacuum suction tube connected to the vacuum apparatus, the vacuum tubepenetrating the transverse partitioning wall; and an annular rimprotrusion extending from the vacuum suction tube, the annular rimprotrusion mating with the second filter end cap via a gasket and abearing, the second filter end cap further comprising a bearing seatacting as an abutment to the bearing. To facilitate portability of thecut off saw, the invention additionally comprises two or more wheels.

In a third aspect, the invention may be characterized as a method forcutting masonry objects comprising the steps of: mounting a circular sawblade piviotably with respect to a worktable; carving out a center slotin the worktable aligned to the circular saw blade; aligning a pluralityof side slots at an angle to the center slot; imparting a negativepressure with respect to atmosphere to an interior of the worktable; andcollecting dust through the center slot and the side slots from the workpiece created as a byproduct from use of the circular saw blade.

The method herein may be additionally characterized as comprising:providing start-up current to a first motor; providing start-up currentto a second motor sequentially to minimize undesirable current surges;providing a cylindrical filter below the worktable; and filtering thedust from air passing through the cylindrical filter. The methodadditionally comprises pleating the cylindrical filter therebyincreasing usable surface area of the cylindrical filter.

Still further, the method for cutting masonry objects herein may becharacterized as comprising: contacting a filter cleaning flap to thecylindrical filter; rotating a filter cleaning knob; clearing dust fromthe cylindrical filter; and collecting dust in a dust bin located at anarea below the worktable. Also the method includes connecting a vacuumtube to a center area of the cylindrical filter; imparting a negativepressure with respect to atmosphere to a center area of the cylindricalfilter; and exhausting filtered air to a lateral side of the worktable.Another method step includes providing a plurality of lifting handles atlateral sides of the worktable.

While the apparatus and method has or will be described for the sake ofgrammatical fluidity with functional explanations, it is to be expresslyunderstood that the claims, unless expressly formulated under 35 USC§112, or similar applicable law, are not to be construed as necessarilylimited in any way by the construction of “means” or “steps”limitations, but are to be accorded the full scope of the meaning andequivalents of the definition provided by the claims under the judicialdoctrine of equivalents, and in the case where the claims are expresslyformulated under 35 USC §112 are to be accorded full statutoryequivalents under 35 USC §112, or similar applicable law. The inventioncan be better visualized by turning now to the following drawingswherein like elements are referenced by like numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself,both as to its structure and its operation, will be best understood fromthe accompanying drawings, taken in conjunction with the accompanyingdescription, in which similar reference characters refer to similarparts, and in which:

FIG. 1 is a perspective view of a preferred chop saw embodiment of thepresent invention;

FIG. 2 is a rear perspective view of a the invention embodimentillustrated in FIG. 1;

FIG. 3 is cross-sectional view of the invention embodiment as takenalong line 3-3 in FIG. 1;

FIG. 4 is a cross-sectional view of the invention embodiment as takenalong line 4-4 in FIG. 1;

FIG. 5A is a close up cut-a-way view of the perspective illustrationshown in FIG. 1;

FIG. 5B is an end view of a filter cleaning knob of the presentinvention;

FIG. 6 is a schematical illustration of a cylindrical filterconfiguration embodiment of the present invention; and

FIG. 7A and FIG. 7B illustrate how an upper housing and a lower dust binrelate to one another.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to FIG. 1, a preferred embodiment 100 comprises acut-off type saw which is configured to cut masonry, and morespecifically stones, bricks, pavers, and other masonry items. It shouldbe understood that inventive concepts herein can also apply towoodworking circular saws and additionally saws for cutting plastic androofing. The dust collection system 100 of the invention works inconnection with a specifically configured saw 201, with a unique cuttingtable 200 and dust collector arrangement. The saw may be a cut-off sawor a chop saw, which has a circular toothed blade 201 or grinding wheel,and which rotates in a vertical plane of rotation as shown. The cut-offsaw is further mounted on a pivotable arm 205 which allows the saw to beraised and lowered from a non-cutting position onto a cutting positionso that the blade contacts a masonry work piece 420, and is loweredthrough the work piece 420 as the saw blade cuts.

In the FIG. 1 embodiment, saw 201 is shown coupled to a saw motor 204.It should be further appreciated that a similar circular saw could becoupled to a belt or pulley system for driving the saw 201. Stillfurther, saw 201 is provided with a cutting table 200 which includes ablade center slot 202. As the cutting blade passes through the workpiece, the blade continues until it enters the center slot 202; andadditionally passes through the surface of the cutting table 200 intothe slot 202. Cutting table 200 should be broadly construed as asubstantially flat structure supporting a workpiece.

As circular blade 201 teeth engage the work piece 420 (FIG. 4), dust andparticulate matter 410 are ejected from the work piece in variousdirections. A negative pressure provided by vacuum apparatus 321 (FIG.3) causes air to flow in a downward direction thereby curtailing outwarddispersion of the dust and particulate matter 410. In conventional priorart systems, the saw blade 201 would not pass through a blade slot, andthus ejected material would strike the cutting table and be collectedafter striking the cutting table. In the saw and dust collection system100 of the present invention, a powerful flow of air is directed pastthe cutting blade 201, through center slot 202 and angled side slots 203and into a filter chamber 310 below the cutting table 200. Alsoimportantly, a flow of air is provided to remove dust at the instant theworkpiece 420 is contacted by the saw blade 201 and throughout thecutting thereof.

With reference to FIG. 2, a rear perspective view of the presentinvention is shown. Exhaust port 211 is provided for discharge offiltered air 330. Air vents 213 provide for ventilation and heattransfer from vacuum apparatus 321. Lifting handles 221, 223 are furtherprovided on first and second lateral sides to assist portability of theunit 100. Electrical connections 212 allow for external power to besupplied to the device 100 as shown.

In a preferred embodiment, system 100 additionally comprises two motors204, 321; a first 204 that drives the saw blade 201 and a second 321that provides a prime mover for air flow. The saw and collection system100 of the present invention may further include a time delay relayassociated with power switch 214. When the saw and collection system isswitched on, a first of two loads 204, 321 is engaged for apre-determined period of time as designed into the time delay relay.Subsequently, a second of the two electrical loads 204, 321 is engaged.By staggering the two starting current surges, the peak load on theelectrical system is reduced. Additionally, this will reduce alikelihood that the system 100 current surge causes a circuit breaker tobe tripped.

Also as shown in FIG. 1 and in FIG. 2, the worktable 200 has twoseparable units, namely upper housing 210 and lower dust bin 220. Inaddition to lifting handles 221, 223 on lateral sides, lifting handles215 are provided on a front and a back of the unit 100 to also serve ashand holds for a user transporting the device. Latch 222 is provided tosecure upper housing 210 to lower dust bin 220 also as shown in FIG. 7Aand FIG. 7B.

With reference to FIG. 3, a sectional view taken along line 3-3 in FIG.1 is shown. Particulate matter 410 from workpiece 420 is drawn throughcenter slot 202 and angled side slot 203. It should also be appreciatedthat side slot could be aligned parallel to the center slot 202 and atright angles thereto. Air containing dust 410 flows as shown bydirectional arrows 330 around partitioning wall 340. Dust 410 is furtherfiltered from the air through cylindrical pleated filter 311. Some ofthe dust and particulate matter will fall to dust bin 220 and some willbe trapped by the filter. Filter cleaning flap 312 is provided connectedto a ledge 313 adjacent to partitioning wall 340. The cleaning flap 312will assist in clearing the cylindrical filter 311 when a user rotatesknob 217. Translational wall 350 serves to separate filter chamber 310from vacuum chamber 320. Exhaust hose 322 is shown in the vacuum chamber320 for exhausting air to an exterior of the device 100. The vacuumapparatus 321 may use various types of motors to generate negativepressure and CFM to include blower motor, centrifugal fan, squirrel cagefan, propeller fan, or any other conventional moving device.

FIG. 4 similarly shows the flow of air with directional arrows 330 as asectional view along line 4-4 of FIG. 1. A cutaway in translational wall350 reveals filter compartment 310. It will be appreciated that otherconfigurations for filter chamber 310 and vacuum chamber 320 could bewell within the scope of the present invention, such as, for example thefilter chamber 310 configured directedly below slots 202, 203.

FIG. 5A shows a closer view of the embodiment 100 in the FIG. 1illustration. The cut-a-way view also reveals a perspective illustrationof the pleated cylindrical filter 311. A carve out in a lateral side ofupper housing 210 is provided to accommodate access panel 218. Filtercleaning knob 217 is connected to the cylindrical filter 311 through theaccess panel 218 as further illustrated in FIG. 6. Access panel 218 canfurther be removed for maintenance and disassembly of the cylindricalfilter 311 for replacement or deep cleaning. FIG. 5 shows an end view offilter cleaning knob 217.

FIG. 6 illustrates more specifically how a cylindrical filter 311connects to a vacuum apparatus 321 via vacuum tube 630 penetratingtransverse wall 350. Initially, filter 311 is supported on it is sidesby filter end caps 610, 620. Knob 217 connects to the first end cap 610via coupler spacing 611 and connection bolt 612. Panel bushing 613provides translational and rotational support to connection bolt 612.Hexagonal nut 614 secures the first filter end cap 610. At the otherend, vacuum tube 630 has an annular rim 631 protruding therefrom andprovides an abutment for bearing 623 also supported by gasket 622.Recess 621 in the second filter end cap 620 provides the space toconnect bearing 623 around rim 631 as shown.

FIG. 7A and FIG. 7B provide a more detailed view of how upper housing210 connects to lower dust bin 220. Rim 710 mates with groove 720 asshown for a secure connection upon closure of latch 222. An inside ofthe dust bin 220 shows an area where dust ultimately settles for laterremoval.

While the particular Chop Saw with Dust Collection System herein shownand disclosed in detail is fully capable of obtaining the objects andproviding the advantages herein before stated, it is to be understoodthat it is merely illustrative of the presently preferred embodiments ofthe invention and that no limitations are intended to the details ofconstruction or design herein shown other than as described in theappended claims.

Insubstantial changes from the claimed subject matter as viewed by aperson with ordinary skill in the art, now known or later devised, areexpressly contemplated as being equivalently within the scope of theclaims. Therefore, obvious substitutions now or later known to one withordinary skill in the art are defined to be within the scope of thedefined elements.

What is claimed is:
 1. A cut off saw comprising: a worktable forsupporting a work piece, the worktable further having four sidesextending downwardly forming lateral portions of a housing; a rotatablearm fixed to a circular saw blade and pivotably secured to theworktable; a center slot carved out of the worktable axially aligned tothe circular saw blade; a vacuum motor apparatus configured within andunderneath the worktable having said four sides extending downwardlyforming lateral portions of said housing, the vacuum motor apparatusproviding negative pressure with respect to atmosphere at the centerslot and collecting dust from the work piece created as a byproduct fromuse of the cut off saw, the housing further comprising an upper housinghaving the vacuum motor apparatus; a saw motor mechanically coupled tothe circular saw blade; and a lower dust bin connected below the upperhousing, the upper housing and lower dust bin each including a frontpanel, a back panel and first and second lateral sides, wherein theupper housing further comprises a lateral partitioning wall extendingfrom first and second lateral sides, and wherein the upper housingfurther comprises a transverse partitioning wall defining both a vacuummotor chamber and a filter chamber.
 2. The cut off saw of claim 1,wherein each of the upper housing front panel and upper housing backpanel further comprise a lifting handle, each of the lifting handlescomprising an indentation in the upper housing front and back panels. 3.The cut off saw of claim 1, the worktable further comprising a pluralityof blade slots angularly aligned to the center slot.
 4. The cut off sawof claim 1, the filter chamber comprising: an access panel covering anarea carved out of the first lateral side; a filter cleaning knobconnected to a first filter end cap via a connection bolt, theconnection bolt penetrating a hole in the access panel; a panel bushingproviding translational and rotational support to the connection bolt; asecond filter end cap, the first and second filter end caps togethersecuring ends of a cylindrical media filter; a vacuum suction tubeconnected to the vacuum motor apparatus, the vacuum suction tubepenetrating the transverse partitioning wall; and an annular rimprotrusion extending from the vacuum suction tube, the annular rimprotrusion mating with the second filter end cap via a gasket and abearing, the second filter end cap further comprising a bearing seatacting as an abutment to the bearing.
 5. The cut off saw of claim 1wherein the upper housing comprises a lower rim, the lower rimcomprising a groove around a perimeter thereof, and wherein the lowerdust bin further comprises an upper rim, the upper rim comprising agroove around a perimeter thereof, and wherein the upper and lower rimscomprising grooves are matingly and removably connected to each other.6. The cut off saw of claim 1 wherein the lower dust bin first andsecond lateral sides each comprise a lifting handle, the lifting handleseach comprising an indentation in the first and second lateral sides,respectively; and wherein the lower dust bin further comprises a latchfor securing the lower dust bin to the upper housing.
 7. A cut off sawcomprising: a worktable for supporting a work piece; a saw motormechanically coupled to a circular saw blade and pivotably secured tothe worktable; a slot in the worktable for receiving dust from the workpiece; a cylindrical media filter at an interior of the worktable, thecylindrical media filter configured to receive the dust from the workpiece via the slot; and a vacuum suction tube coupled to an interior ofthe cylindrical media filter providing negative pressure with respect toatmosphere to said interior of the cylindrical media filter.
 8. The cutoff saw of claim 7, wherein the slot is a center slot carved out of theworktable and axially aligned to the circular saw blade, and wherein thecut off saw further comprises a plurality of blade slots angularlyaligned to the center slot.
 9. The cut off saw of claim 7, furthercomprising a filter chamber containing the cylindrical filter, thefilter chamber further comprising a filter cleaning flap secured to alateral partitioning wall at an interior of the filter chamber, thecylindrical filter media having a plurality of pleated segments about acylindrical surface, wherein the filter cleaning flap contacts thepleated segments when a filter cleaning knob is rotated.
 10. The cut offsaw of claim 9, the filter chamber further comprising: an access panelcovering an area carved out of the first lateral side wherein the filtercleaning knob is connected to a first filter end cap via a connectionbolt, the connection bolt penetrating a hole in the access panel. 11.The cut off saw of claim 10, the filter chamber further comprising: apanel bushing providing translational and rotational support to theconnection bolt; and a second filter end cap, the first and secondfilter end caps together securing ends of a cylindrical media filter.12. The cut off saw of claim 11, wherein the vacuum suction tube isconnected to a vacuum apparatus, the vacuum suction tube penetrating atransverse partitioning wall, wherein the filter chamber furthercomprises an annular rim protrusion extending from the vacuum suctiontube, the annular rim protrusion mating with the second filter end capvia a gasket and a bearing, the second filter end cap further comprisinga bearing seat acting as an abutment to the bearing.
 13. A cut off sawwith a dust collection system comprising: a worktable for supporting awork piece, the work table having a top, a bottom and a plurality oflateral sides providing a housing and defining a hollow housinginterior; a rotatable arm fixed to a circular saw blade and pivotablysecured to the worktable; a saw motor mechanically coupled to thecircular saw blade; a vacuum motor providing negative pressure withrespect to atmosphere to the hollow housing interior, the vacuum motorfurther configured inside the hollow housing interior; a lower dust binapproximately at the bottom of the worktable for collecting and holdingdust from the work piece created as a byproduct from use of the cut offsaw; a cylindrical filter configured to the hollow housing interior; afilter cleaning knob coupled to the cylindrical filter for rotating thecylindrical filter and assisting cleaning thereof; and a vacuum suctiontube connected to the vacuum apparatus, the vacuum suction tube furtherconfigured to an interior of the cylindrical filter.
 14. The cut off sawof claim 13, the worktable further comprising: a center slot axiallyaligned to the circular saw blade; and a plurality of slots angularlyaligned to and about the center slot.